Adesso iMouse T40 Wireless Ergonomic Finger Trackball Mouse with Nano USB Receiver, Programmable 7 Button Design, and 5 Level DPI Switch, for Left and Right Hand: Mice: Amazon.com.au
Perixx PERIMICE-520 Wired USB Ergonomic Programmable Trackball Mouse, Adjustable Angle, 8 Button Design, Black (PM-520-11447): Mice: Amazon.com.au